The present invention relates to a novel and useful hydroquinone derivative and intraocular pressure lowering, antihypertensive and radical scavenging compositions containing thereof as an active ingredient.
Previously the present inventors successfully synthesized certain novel propanol derivatives and found that those compounds are useful as antihypertensive as well as anti-glaucomatous agents (Unexamined Japanese Patent Publication H7-157455). An antihypertensive agent and a dysuria treating agent in prostatic hypertrophy have also been known both of which contain a naphthol derivative, 1-phenyl-4-[3-(naphth-1-yl-oxy)-2-hydroxy-propyl]piperazine, as an active ingredient, [Unexamined Japanese Patent Publication H3-31271]. Furthermore, certain benzylalcohol derivatives have been disclosed which have an xcex11-adrenergic receptor blocking activity with less side effect of orthostatic hypotension, and which are useful for glaucoma and ocular hypertension [Unexamined Japanese Patent Publication H9-12563].
The present inventors have further investigated relating compounds to the above and their pharmacological effects, and, as a result, have successfully synthesized a group of novel hydroquinone derivatives and found that they have potent intraocular pressure lowering, antihypertensive and radical scavenging activities. The present invention has been made on the basis of these findings and through further investigation.
Thus, the present invention relates to: (1) A hydroquinone derivative represented by the following formula: 
wherein B1 and B2 in formula (I) are the same or different and at any position on the benzene ring (when W is nitrogen, however, at any other position on the benzene ring) and each denotes a substituent selected from the group consisting of hydrogen, halogen, hydroxyl, lower alkoxyl and carboxyl, and the substituent CH3 is at position 2 or 3, and W are the same or different and each denotes a nitrogen or carbon atom. R1, R2, R3 and R4 in formula (II) are the same or different and each denotes a substituent selected from the group consisting of hydrogen, lower alkyl and lower alkoxyl, and B1 and B2 are as hereinbefore defined, or a pharmacologically acceptable salt thereof (hereinafter referred to as xe2x80x9cthe present compoundxe2x80x9d), and (2) intraocular pressure lowering, antihypertensive and radical scavenging compositions containing thereof